WAVE HEIGHT ESTIMATION BY USING WAVE SOUND FROM AN IC RECORDER AT THE HASAKI COAST, JAPAN

Abstract

 Field experiments were conducted at the Hasaki Oceanographical Research Station (HORS), located on the Hasaki coast in Ibaraki prefecture, to investigate the correlation between sound pressure levels and wave heights. The wave sound levels were observed 114 m landside from the average shoreline position and 11.6 m above the average sea level. The observed hourly data from October 20th to November 17th 2020 were used in the analysis. First, the significant wave height was estimated using the data measured by the sound level meter. It was confirmed that the estimation results show an almost similar trend compared to the previous studies (R² = 0.51). Next, significant wave height values were estimated with an IC recorder. The sound pressure level and relative deviation by the IC recorder and wind speed were used to estimate the wave height. However, the highest correlation coefficient was R² = 0.15. Therefore, relationship formula was derived between the significant wave height and the IC recorder's sound pressure level using the preceding 1.5 days data. Furthermore, the formula was used to estimate the significant wave height for the following 12 hours. As a result, although there was a slight time delay, it was found that the wave heights can be estimated with a good accurately (R² = 0.64).